Haiti’s president has blasted the British aid charity Oxfam for allowing an “extremely serious violation of human dignity” following revelations that senior staff held orgies with prostitutes while delivering aid after the 2010 earthquake.

President Jovenel Moise addressed the growing sexual exploitation scandal on his Twitter account Monday, writing in French: “There is nothing more outrageous and dishonest than a sexual predator who uses his position as part of the humanitarian response to a natural disaster to exploit needy people in their moment of greatest vulnerability.”

Oxfam, one of the world’s best known humanitarian NGOs, has been under fire following a report in The Times of London Friday that the group had concealed the findings of a 2011 inquiry that found that senior staff had regularly used local sex workers in the wake of the devastating 2010 earthquake.

Oxfam has confirmed that the misconduct that occurred, and said that seven staff members were dismissed or resigned after the internal investigation, but denies any cover up took place.

Haiti’s president has blasted the British aid charity Oxfam for allowing an “extremely serious violation of human dignity” following revelations that senior staff held orgies with prostitutes while delivering aid after the 2010 earthquake.

President Jovenel Moise addressed the growing sexual exploitation scandal on his Twitter account Monday, writing in French: “There is nothing more outrageous and dishonest than a sexual predator who uses his position as part of the humanitarian response to a natural disaster to exploit needy people in their moment of greatest vulnerability.”

Oxfam, one of the world’s best known humanitarian NGOs, has been under fire following a report in The Times of London Friday that the group had concealed the findings of a 2011 inquiry that found that senior staff had regularly used local sex workers in the wake of the devastating 2010 earthquake.

Oxfam has confirmed that the misconduct that occurred, and said that seven staff members were dismissed or resigned after the internal investigation, but denies any cover up took place.

The scandal has since spread, following revelations that a staff member at the center of the Haiti scandal had previously been accused of regularly meeting with sex workers while working for the organization in Chad. Despite knowing of the complaints, Oxfam later transferred him to Haiti.

The British government and European Union have threatened to cut funding to the organization over its handling of the scandal, with Britain’s international development secretary, Penny Mordaunt, saying that Oxfam would receive no more public money unless it demonstrated “moral leadership” and handed over all information on the case.

She said the organization had failed to live up to his responsibilities by not stopping the alleged perpetrators from going to work for other organizations, she said.

Oxfam's deputy chief executive Penny Lawrence resigned Monday, saying her organization had failed to respond adequately when concerns were raised about the behavior of the staff in question.

“As program director at the time, I am ashamed that this happened on my watch and I take full responsibility,” she said.

The scandal threatens to impact on the British aid sector more broadly, with Priti Patel, the former international development minister, describing the Haiti case as “the tip of the iceberg” and warning of a “culture of denial” in humanitarian organizations. Her successor, Mordaunt, says she believes that sex predators could be be targeting aid organizations because of the potential to exploit vulnerable locals in the chaotic environments they operate in.

Accusations of sexual misconduct in conflict and disaster zones are not limited to humanitarian groups. Last year, the Associated Press, citing an internal U.N. document, reported that more than 100 Sri Lankan U.N. peacekeepers had run a child-sex ring in Haiti for years. None were punished, according to the report.

Cover: A latrine project led and financed by Oxfam, at the tent camp where 55,000 displaced Haitians were living on the grounds of what was the Club de Petionville on January, 2011 in Port-au-Prince, Haiti. (Photo by Jonathan Torgovnik/Getty Images)